The present invention relates to a structure which enables a rod-shaped antenna element to be mounted on a casing body of a portable phone or the like. The antenna element is movable between a position accommodated within the casing body and a position withdrawn from the casing body.
FIGS. 13A and 13B show a conventional structure for mounting a rod-shaped antenna. FIG. 13A shows the accommodated position, and FIG. 13B shows the withdrawal position.
In this example, a casing body 10 is provided with a receiving holder 12 which is fixed thereto. A holder 14 made of conductive material is fixed to this receiving holder 12, having a male thread 14a formed in the holder 14 screwed into a female thread 12a formed in the receiving holder 12. A rod-shaped antenna element 16 is arranged in this holder 14 so as to be movable in an axial direction thereof.
The rod-shaped antenna element 16 includes power supply parts 16a, 16b made of conductive material, at positions respectively opposed to the holder 14 in either of the accommodated position and the withdrawal position. The holder 14 is provided with a power supply spring 18 made of conductive material so as to be brought into elastic contact with the power supply parts 16a, 16b, so that electrical connection is established between the power supply parts 16a, 16b and the holder 14 by way of this power supply spring 18. Further, a power supply terminal 20 which is provided in the casing body 10 is brought into elastic contact with the holder 14, so that the power supply parts 16a, 16b of the rod-shaped antenna element 16 are electrically connected appropriately to an electrical circuit which is contained in the casing body 10. A top loading 22 is further provided on the rod-shaped antenna element 16.
The holder 14 is relatively heavy, because it is made of conductive metal. Moreover, the receiving holder 12 is also heavy, because it is generally made of metal, in order to form the female thread 12a. Under the circumstance, as the antenna mounting structure for the portable phone or the like which is desired to be light-weight.